Extensive urbanization has greatly raised the demand for cleaner coal- and petroleum-derived fuels. Mainly composed of methane, natural gas represents a promising alternative for this purpose, making its storage a significant topic. In the present research, deposition of methane molecules in C60 fullerene was investigated through a combined approach wherein density functional based tight binding (DFTB) method was used to optimize the geometry while ab initio density functional theory (DFT) served as a tool for energy calculation. Doping endohedral methane molecules onto fullerene nanocage, it was witnessed that, the only stable complex might be formed by a single methane molecule entrapped inside the C60 cage. It was further indicated that, when a large number of encapsulated CH4 molecules are concerned, occasional chemisorption of the molecules on the inner surface of the cage would occur, ending up breaking the capsule side wall at NCH4=7. Further studied by density-functional tight-binding molecular dynamics (DFTB-MD) simulation, mechanism of the breakage indicated this complex as being highly unlikely to be stable. پرونده مقاله

The interaction between nanoparticles and biomolecules such as protein and DNA is one of the major instructions of nanobiotechnology research. In this study, we have explored the interaction of adenine nucleic base with a representative golden cluster (Au13) by using dispersion corrected density functional theory (DFT-D3) within GGA-PBE model of theory. Various active sites as and ways of approach as well as several affecting parameters on the interaction nature of interacting molecules such as adsorption energy, binding distance, solvent effect and, electronics structure were investigated. Our first-principles results indicated that adenine forms a stable complex with the golden cluster with interaction energy of –42.84 kcal/mol and binding distance of 2.139 Å. Charge transfer analysis with Hirshfeld approach demonstrated about 0.52 e was transferred from adenine to golden cluster skeleton. It was found from the obtained interaction parameters that there is strong interaction (chemisorption) between adenine and golden cluster. The type and strength of interaction have been also confirmed by hybrid functional B3LYP level of theory. This finding is very promising for potential medicinal and pharmaceutical applications of golden clusters. پرونده مقاله

The interaction between nanoparticles and biomolecules such as protein andDNA is one of the major instructions of nanobiotechnology research. In this study,we have explored the interaction of adenine nucleic base with a representativegolden cluster (Au13) by using dispersion corrected density functional theory(DFT-D3) within GGA-PBE model of theory. Various active sites as and ways ofthe approach as well as several affecting parameters on the interaction nature ofinteracting molecules such as adsorption energy, binding distance, solvent effectand, electronics structure were investigated. Our first-principles results indicatedthat adenine forms a stable complex with the golden cluster with interactionenergy of –42.84 kcal/mol and binding distance of 2.139 Å. Charge transferanalysis with Hirshfeld approach demonstrated about 0.52 e was transferred fromadenine to golden cluster skeleton. It was found from the obtained interactionparameters that there is strong interaction (chemisorption) between adenine andgolden cluster. The type and strength of interaction have been also confirmed byhybrid functional B3LYP level of theory. This finding is very promising for potentialmedicinal and pharmaceutical applications of golden clusters. پرونده مقاله

Bacteria can grow in different materials that are in close contact with humans, foods, etc., so, it is very important to control this matter in order to prevent risk of infections. Antimicrobial resistance (AMR) threatens the effective prevention and treatment of an ever-increasing range of infections caused by bacteria, parasites, viruses and fungi. Multiwall carbon nanotubes (MWNTs) have interesting antibacterial activities and offering a promising new treatment preventing bacteria from becoming resistant. With this aim, we report for the first time three novel modified carboxylated multiwall carbon nanotubes consisting of MWNT–CO-Metformin, MWNT–CO- [Metformin][CuCl2] and MWNT–CO-[Metformin][AgNO3]. The functionalized carboxylated multiwall nanotubes were then characterized by FT-IR, Raman, TEM, EDX and Elemental analysis. Moreover, the antibacterial activity of all of compounds has been investigated against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. These results show that nano compounds exhibited significant antibacterial activity and have a potential to be used as antibacterial agent. پرونده مقاله

In this research, synthesized well derivatives of 1,3-diaryl-2-N-azaphenalene and N-acyl-1.3-diaryl-2-N- azaphenalene as a macromolecule in the presence of nanoparticles (Fe3O4 coated with L-Arginine)as a magnetic Nano catalyst in a one-pot reaction of compounds 7.2-Naphthalene diol, aldehydes,ammonium derivatives (ammonium acetate or ammonium hydro phosphates) and solvent (waterand alcohol) with high yield and short reaction times, economical and simple workup. In this study,apart from the innovation in the synthesis of a macromolecule, the antibacterial activity of thesecompounds was evaluated for the first time. The reaction was doe under very moderate conditionsat room temperature. The chemical structures of all synthesized compounds were determined usinginfrared, 1H NMR and 13C NMR spectroscopies. After the production of nanoparticles, the structure ofthe obtained nanoparticles was characterized via Fourier transform infrared spectroscopy (IR) and fieldemission scanning electron microscopy (FE-SEM). The results demonstrated that the average size ofthe synthesized magnetite nanoparticles is about 21 nm. The heterogeneous catalyst used was easilyseparated magnetically and reused without any significant loss of catalytic activity and magnetism.Eventually, antibacterial activity of the synthesized compounds was investigated by Escherichia coli(ATCC: 25922) and Pseudomonas aeruginosa (ATCC: 27853) as gram negative bacteria, Staphylococcusepidermidis (ATCC: 14990) and Staphylococcus aureus (ATCC: 29213) as gram positive bacteria. Someof these products exhibit significant antibacterial activity. پرونده مقاله

Background & Aim:Medicinal plants are rich sources of substances with nutraceutical and health benefits. Valeriana officinalis L. (Valerianaceae) is a known medicinal plant used in traditional medicine throughout the world. The present study aimed to evaluate the efficiencies of three methods for antioxidant extraction from Valeriana officinalis, and the impact of extraction methods on total phenollic and flavonoids contents and antioxidant activities of valeriana root was studied. Experimental: The dried-root was extracted by three different methods including maceration, ultrasonic assisted, and Soxhlet assisted extraction. Antioxidant capacity of the extracts was assessed using DPPH and nitric oxide (NO) free radicals scavenging, reducing power and iron chelating activity. Total phenolic and flavonoid contents were also identified. Results: The ultrasonic extract showed the highest amount of total phenolics and flavonoids contents. In DPPH radical scavenging activity and reducing power assay, the ultrasonic assisted extract, (IC50=0.546 mg/ml) showed higher activity than the other extracts. In DPPH radical scavenging activity, IC50 for ultrasonic extract, soxhlet assisted extraction and maceration extract were 0.546, 0.816 and 0.678 mg/ml, respectively. The results clearly showed that the extraction methods used in this study significantly affected antioxidant capacities and total phenolic and flavonoids contents. It was found that ultrasonic assisted extraction and Soxhlet methods are more efficient in extraction of antioxidant components from Valeriana officinalis L. Recommended applications/industries: Considering result of study, it can be inferred that the herb may be a good source of bioactive compounds and can work as an antioxidant to prevent the oxidative deteriorative activity of food materials. پرونده مقاله

In this research, effects of SiO2 nanoparticles (NPs) on the growth, antioxidant properties, and phenolic and flavonoid contents were investigated in Anthemis gilanica plants from the Asteraceae family. Following seed germination, seedlings were cultured under Hoagland growth media and were treated with different concentrations of SiO2NPs (0, 2, 4, 6 and 8 g L-1). The results showed that SiO2 NPs significantly enhanced relative water content (RWC), dry and fresh weights, and shoot length especially at 4 g L-1, but decreased root length with increasing concentrations of NPs. Xylem number and size, and stele diameter increased up to 6 g L-1, and then decreased at higher concentration. Total phenol and flavonoid contents increased under different concentrations of SiO2 NPs, and the maximum content was observed at 6 g L-1. Moreover, SiO2 NPs increased antioxidant activity of extracts by reducing IC50 content especially at 6 g L-1. In conclusion, this study proposes that SiO2 NPs can improve growth and bioactive compounds in A. gilanica by induction of anatomical alterations. پرونده مقاله